Packaging and storage— Preserve in tight containers.

USP Reference standards á11ñ— USP Erythromycin RS.USP Erythromycin Estolate RS.

Identification— Prepare a test solution by mixing a quantity of Capsule contents with methanol to obtain a concentration equivalent to about 20mg of erythromycin per mL.Prepare a Standard solution of USP Erythromycin Estolate RSin methanol containing the equivalent of 20mg of erythromycin per mL.Apply separately 3µLof each solution to a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Proceed as directed in the Identificationtest under Erythromycin Delayed-Release Capsules,beginning with “Place the plate in an unlined chromatographic chamber.”

Disintegration á701ñ: 30minutes,proceeding as directed for Hard Gelatin Capsules,except to use disks and to use simulated gastric fluid TSas the immersion fluid instead of water.

Uniformity of dosage units á905ñ: meet the requirements.

Water,Method Iá921ñ: not more than 5.0%,20mLof methanol containing 10%of imidazole being used in place of methanol in the titration vessel.

Assay— Place not less than 4Capsules in a high-speed glass blender jar with 200.0mLof methanol,and blend for 3minutes.Add 300.0mLof Buffer No.3,and blend for 3minutes.Allow this solution to stand at room temperature for 18hours.Proceed as directed for erythromycin under Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of this stock test solution diluted quantitatively with Buffer No.3to yield a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 763

Phone Number:1-301-816-8335